Pptx file converter for office 2007 to office 2003

you can open ppsx in this
http://www.microsoft.com/downloads/en/details.aspx?FamilyID=cb9bf144-1076-4615-9951-294eeb832823
or in this
www.openoffice.org

you can open the file on office 2007 convert it to 2000 2003
Until you get office 2007

PPTX is Powerpoint 2007 format. Microsoft has a free viewer for that version if you dont have Office at all, available at http://www.microsoft.com/downloads/details.aspx?familyid=048DC840-14E1-467D-8DCA-19D2A8FD7485&displaylang=en You will only be able to view, not edit the document using this viewer.

As an alternative, if you have the 2003 Office suite, you can download the compatibility pack which will allow you to open .pptx files in Powerpoint 2003, .docx in Word 2003, etc. That download is located at http://www.microsoft.com/downloads/details.aspx?FamilyID=941b3470-3ae9-4aee-8f43-c6bb74cd1466&displaylang=en

Say you got tons of Excel sheets, PowerPoint presentations and Word documents on your computer that were written in Office XP or 2003. How do you convert all these files to the new Office 2007 format. One option is that you open all of them in the associated Office program and manually save them in the newer (docx, xlsx or pptx) format. Or follow these steps and convert all documents in one go.
Step 1: Download Migration Manager kit and extract it into a new folder – say: c:\office.

Step 2: Download and install the Office Pack – this step is required even if you have Microsoft Office 2007 already installed on your computer.
Step 3: Assuming that you extracted the Office Manager files in c:\office directory, go c:\office\tools, open ofc.ini using notepad and add the following line.
fldr=c:\users\labnol\documents
This refers to the folder location that holds your office files. I am pointing this to my Documents folder but it could be different on your machine.
Step 4: Open command prompt and go to c:\office\tools. There you’ll see a utility called ofc.exe – this is the Office File Converter that will convert all old Office files to the new 2007 Office document format in bulk. Run.

Immediately all old Office files in that folder (and sub-folders) will get converted to the new format and are saved in a new folder.
This utility works with Word (doc to docx), Access databases, PowerPoint (ppt to pptx), Visio diagrams, Excel (xls to xlsx) and Microsoft Project files. The conversion may however fail for password protected documents.